It probably will scrape. My boyfriend has a '96 240 (yes, I'm VERY jealous) with 17X7 and does not have a problem turning at all. He actually did in the beginning because he'd had an accident with his car, so one of his mud-guards wasn't positioned right and it scraped off the tire. He went back to the body shop and got it fixed and now it's "just perfect". So I'm thinking if 17x7s did it to a mud-guard that was off-position by less then an inch, you might get a scrape from 16x8s. But then again, they're free, it doesn't hurt to try. I'd like to  know how it goes!